Project Abstract The transition from adolescence to adulthood is particularly challenging for individuals with autism spectrum disorders (ASD). The ability to drive a vehicle has great potential to increase independence and mobility for teens with ASD?ultimately improving long-term well-being and health. We know that 1 in 3 individuals with ASD are licensed by age 21, but there is a notable gap between these families' interest in driving and the percentage of teens who are actually driving. For teens with ASD who do drive independently, impairments in skills known to be critical for safe driving may put them at heightened risk of a motor vehicle crash?the leading cause of death among teens. Given both the importance of safely encouraging independence and the potential for increased risk for negative driving outcomes, research on driving among teens with ASD is critical. Our long-term goal is to develop tailored resources and interventions that support teens with ASD and their families during the transition-to-driving period and optimize both their safety as independent drivers and positive long-term health outcomes. The overall objective of this research project is to provide much-needed evidence to directly inform development of these driving supports for teens and young adults with ASD. We will conduct an integrated series of three studies to: (1) identify underlying factors and outcomes of families' driving decisions; (2) characterize the driving patterns, behaviors, and performance of licensed teen drivers with ASD; and (3) establish the risk of negative driving outcomes among teen drivers with ASD. In Aim 1, we will first conduct qualitative interviews with driver educators, healthcare providers, and teens with ASD and their parents. Results will then directly inform quantitative surveys employed in a longitudinal cohort study of more than 500 teen with ASD-parent dyads that aims to determine how teens and their parents decide to drive and assess whether driving is associated with higher rates of quality of life measures. In Aim 2, we will characterize the driving patterns, behaviors, and performance of 40 newly licensed teens with ASD by continuously monitoring their driving for the first 12 months of licensure via innovative in-vehicle technology. We will estimate the prevalence of driving exposure (e.g., miles driven) and unsafe driving behaviors (e.g., speeding, cell phone use) among teens with ASD and compare the rates of unsafe driving events to a sample of teens without ASD derived from a prior naturalistic driving study. In Aim 3, we will conduct a retrospective cohort study using a unique linked data warehouse of childhood electronic health records and state traffic safety data to compare the risk of motor vehicle crashes and traffic citations for licensed teen drivers with and without ASD over the first four years of licensure. This study is innovative in that it is the first longitudinal research program to investigate real-world driving outcomes among teens with ASD. We expect that results generated from this project will lead to identification of new targets of driving interventions and programs for teens with ASD, provide knowledge about important aspects of the decision-making process for families during the transition-to-driving period, and ultimately improve the safety of drivers with ASD.